1. Field of the Invention
This invention relates to a numerically controlled coil winding machine for manufacturing coils for electronic use. More particularly, this invention relates to a turret coil winding machine in which the wire winding guide is driven in known manner to rotate about the X axis and to slide along the same X axis, while the winding support is made to slide along the Y and Z axes under numerical control, to enable several separate winding mutually spaced apart on said support to be formed.
2. Description of the Prior Art
It has been known for some time to use numerical control in machine tools, for example milling, boring and drilling machines and the like. The principle on which this numerical control operates is therefore widely known, and it is consequently considered unnecessary to illustrate it in this description.
Relatively recently it has been proposed to apply numerical control to machines operating in the electronic component production field. One example of such an application is in the mass production of printed circuits, in which the various perforations in the printed circuit are made in accordance with a predetermined circuit diagram by several drilling bits operating in parallel, their position relative to the printed circuits being determined by numerical control. Likewise, numerical control has been applied to trimming integrated circuits, and only recently has it been considered for coil winding.
In this latter case, coil winding machines are known in which several coil supports are fixed on a support plate disposed in a horizontal or vertical plane, the plate being moved in this plane in two perpendicular directions. This plate movement is used to cause the axes of the individual coil supports to each coincide in succession with the axis of the wire guide which effects the winding.
A coil winding machine based on this operating concept is evidently conceived with the purpose of obtaining a high productivity rate, in that besides producing several windings simultaneously, it eliminates a large part of the down times necessary for the mechanical replacements required in known machines, it being necessary in this case to change only a punched or magnetic tape.
However, this machine has a limited use mainly because it is able to make only one winding or additionally, at the most, to twist together the coil terminals, these being operations which may both be performed by the same wire guide, in accordance with a predetermined winding programme.
If however it is required to produce a somewhat more complicated coil, for example a coil with two superimposed windings of different characteristics, it is impossible to produce this automatically with the aforesaid numerically controlled machine.
In this respect, with such a machine it is necessary to remove the coil after the first winding and start again for each subsequent winding, thus considerably reducing productivity. It must be remembered that in this machine, the times required for loading and removing the workpieces are effectively down times because the machine is at rest during these stages.
In the coil winding field, turret coil winding machines, with which completely finished complicated coils may be obtained, are much more widely used.
These machines are based on a different operating concept. The empty coil supports are loaded on to support pins which project radially from support positions in a machine turret which rotates stepwise, and are transferred in succession through various fixed working stations in the machine. These stations may each execute one of the required operations, namely the basic winding operation preceded and/or followed by winding the terminals, then the complementary stages of soldering the terminals, waxing, taping or the like, then possibly a second winding, and so on.
In these machines, each support position on the turret comprises either only one support pin with only one wire guide in each winding station, or as many support pins as there are wire guides in each winding station. Up to the present time it has not been felt necessary to combine both the aforesaid operating concepts in a single machine, i.e. to provide a turret coil winding machine in which a support plate, capable of supporting a number of coils equal to a multiple of the number of wire guides, is associated with each support position, as a replacement for the support pin or pins. In effect, this would create a machine in which, not only would the turret have to be moved to shift each support position through the successive working stations so as to stop it in a single well determined position in each working station, but in addition said support plate would, in some way or another, have to be moved relative to the respective support position, so as to be placed in different pre-established positions in each working station. In reality:
on the one hand, it was not evident what advantages could be obtained from a method of this type compared with a normal turret coil winding machine, considering that the production rate would be increased by an insignificant amount. In this respect, the down times involved in loading and removing the coils would be contained within the winding times (seeing that in turret machines, the loading in any given station is being carried out at the same time as the winding in another station), and the down times involved in moving the coil supports from one working station to another would be comparable to the times involved in moving and positioning a support plate for several coils in front of the wire guide, even in a numerically controlled machine; PA0 on the other hand, even if some small productivity advantage could be envisaged in a machine of this construction, the complication of conceiving a support plate movable along the Y and Z axes, the cost of a numerical control unit associated with each turret position to govern such a movement, and the difficulty of making the connection between the movable turret position and the necessarily fixed numerical control unit have discouraged such an application up to the present time.
However, the requirement has arisen in recent times for an assembly consisting of several identical interconnected electrical coils formed into an inseparable complete unit. An assembly of this type is required for example in telephone exchanges, and generally comprises a baseplate on which several identical coils, each formed from two superimposed windings, are disposed for example in a number of perpendicular rows and columns.
The constructional method used at present for making this assembly is to utilise identical coils from any mass production, and then connect them suitably together.